Seasons and the calendar year

Meteorological seasons

Meteorologists commonly group seasons into three-month blocks for consistent statistics. The month groups differ between the Northern and Southern Hemispheres.

Astronomical seasons

Astronomical seasons are bounded by solstices and equinoxes. Their exact instants vary slightly from year to year.

Location changes the picture

Tropical, polar and local climate patterns may not fit a four-season model. Calendar labels are useful conventions, not a universal description of weather.

Related year guides

• Calendar quarters explained — See which months belong to Q1, Q2, Q3 and Q4.
• Leap years explained — Learn the Gregorian leap-year rule and why February sometimes has 29 days.
• What day number is today? — Understand ordinal dates and find today's position in the year.